Internal combustion engine apparatus



R. N. CRABTREE r-:r AL

INTERNAL COMBUSTION ENGINE APPARATUS Filed July 30, 1940 Feb. 23, 1943.

A 44 m/V. 62452255 6.440%. 54 00;

IN V TORS A TTORNEYS.

Patented Feb. 23, 1943 INTERNAL [COMBUSTION ENGINE APPARATUS Ralph N. crabtre'and Glaud A. Brooks, San Bernardino, Calif.

Application July 30; 1940, Serial No. 348,412

7 Claims. (Cl. 123-419) This invention relates to internal combustion engine apparatus, and particularly to such apparatus in which the gases of combustion from the engine are utilized to assist in vaporizing the liquid fuel by direct contact with the same. We are aware that heretofore a construction has been disclosed for this purpose in a patent granted to C. A. French, No. 2,071,116, February 16, 1937, and in which an automatically controlled valve was disposed in an exhaust pipe leading from the exhaust manifold, and in front of this valve with respect to the direction of flow of the gases, a Pitot tube was employed to circulate some of the gases of combustion through a bath of the liquid fuel in a vaporizing chamber from which the vaporized mixture flowed to the venturi of the intake. The apparatus referred to, however, did not provide any means for admitting air to the vaporizing chamber, and it depended entirely upon the admission of the air for combustion at the venturi. In the operation of the apparatus disclosed in the patent, it was necessary to use some means for initially effecting a vaporization of fuel to start the engine. In other words, it would not start readily with the apparatus for circulating the exhaust gases through the bath of liquid fuel.

One of the objects of the present invention is to provide an engine apparatus of this type, with means for enabling the gases of combustion from the engine to be employed to increase the vaporization of the fuel when the engine is running,

Further objects of the invention will appear hereinafter.

The invention consists in the nov l parts and combination of parts'to be described hereinafter, all of which contribute to produce an efficient internal combustion engine apparatus.

but at the same time to provide a construction which will enable the engine to be started without relying on the presence of the exhaust gases; also to provide such apparatus with means for insuring an ample supply of'air for combustion, and for mixing the same effectively Withthe vaporized fuel.

A further object of the invention is to provide an apparatus of this type with means for effecting a very nice regulation of the quantity'of air admitted for supporting the combustions or explosions in the engine; also to provide means whereby the quantity of air admitted, adapts itself'automatically to the quantity of air required, but with additional means for further regulating additional air at the point of admission into the intake.

A further object of the invention is to provide apparatus of this kind with means to insure a thorough mixture of the volatilized fuel and the air for combustion, at the same time insuring that no droplets of unvaporized. fuel can pass into the engine.

A preferred embodiment of the invention "is described in the following specification, while'ttie broad scope of the inventio'n'is pointed out in the appended claims.

In the drawing:

Fig. 1 is a viewof a diagrammatic natureand illustrating elements of "the invention. In this view certain parts are broken away-and shown partly in section.

Fig. 2 is a vertical 'section' take'n abouti'n the plane-of theline 2-' 2 of Fig.1, and looking in the'direction indicated 'by th'e'arr'ows.

Fig. 3 is a fragmentary view, and-is-a vertical section taken at about the location of the line 33 in Fig. '1, and illustrating" details of an automatic feeding apparatus 'for-maintaining-the level of the supply of liquid in the"*vaporizing chamber.

Fig. 4 -'is a fragmentary view,'and is a vertical section taken through the air inlet-29, with parts broken away. This view illustrates the mounting of the fa'nin the air inlet.

In practicing the invention, we provide a rec'eptacle for maintaining a quantity of a volatile liquid fuel. a'nd we provide means for passing 5 the hot exhaust gases from the engine through this liquid tovaporize the same; we alsoprovide'a duct for leading the fuel vapors to the intake, and an air inlet for admitting air to-fiow through the duct with the fuel vapors. The apparatus preferablyincludes movable ineansllocatedin tl're air inlet and actuated by the 'infiowing air for automatically admitting an 'increased quantity of atmospheric air as the degree of partial-vacuum in the engine intake increases incidentally to the increased speed of the engine. In this way the supply of air m; combustion is auto matically dependent upon the speed of the engme.

In the preferred "embodimentof' the invent'ioh, the hot {gases from the engine are {admitted by means of a bifurcated pipe blo'w ';the}1ev1'dr the liquid fuel, and as these gases pass up through the numerous perforations, they pass through the liquid and ifectively vaporizeit. This action "occurs in the vaporizing -'"chamber to Which most-of the an rq'r combustion is admitted. As thes'e' fu'el vapors and air 'for'coinbustioh 1 are conducted -toward the engine' intakaa thorough mixture of them is effected preferably by means of bafiles in the path of flow of these gases.

Referring to the drawing, l indicates an engine casing, for example, a cylinder block in which reciprocating pistons operate, said casing being provided with an exhaust duct or manifold 2 into which the exhaust gases from the cylinders pass.

A portion of the gases of combustion is conducted to a vaporizing chamber or compartment 3 that may be designed as a part of a tank 4 that includes a reservoir 5 for the liquid fuel 6. This fuel flows through a pipe connection 1 and a regulating valve 8 to a fluid-control valve 9.. As the level of the bath or pool ll] of liquid fuel.

in the vaporizing chamber 3 rises and falls, it controls the position of the float II, which will open the valve 9 further when the liquid level falls, and vice versa.

In order to conduct hot gases of combustion to the vaporizing chamber, we prefer to provide an exhaust gas heater l2 (see Fig. 1) which is connected by a plurality of short pipes l3 to the interior of the exhaust manifold 2. These short pipes are located at different points, preferably near the exhaust valves for the different cylinders. In other words, they are distributed about equally along the length of the exhaust manifold 2. Hence when the engine is in operation, these exhaust gases from the different cylinders will accumulate in the header l2.

This header is connected by means such as the pipe 14 with a perforated pipe or nozzle l5 that extends longitudinally near the bottom of the vaporizing chamber and below the level of the liquid Ill. The combustible or explosive mixture is'conducted from the vaporizing chamber 3 to the intake 16 of the engine, through a duct or pipe 11 which extends along and preferably surrounds the pipe line I4. This inlet duct I'l connects into the venturi l8 of the intake l6, preferably through a cover plate I!) that closes the lower end of the venturi. The principal air for combustion is preferably admitted through an air port or inlet 20, which is preferably located at a point in the vaporizing chamber 3 remote from the point 21 or outlet point where the explosive mixture passes out of the vaporizing chamber. In practice this inlet 20 is preferably located at one end of the tank 4, and the outlet 21 at the other end. This gives a considerable space between these points for a thorough mixture of the incoming air and the vaporized fuel to occur. In order to insure a thorough admixture of this air, we prefer to provide baffles or similar means for effecting this mixture within the vaporizing chamber. For this purpose we may employ baffles such as the bafiles 22 and 23 illustrated in Figs. 1 and 2. The lower baffle 22 includes two inclined plates and perforations 24 near their lower edges through which the vapors pass up-, wardly, and the upper baffle 23 is formed with inclined plates that guide the vapors up to perforations 25. These bafiles 22 and 23 may be considered as substantially horizontal balfles, as they are disposed in a nearly horizontal plane. In addition to this we prefer to provide one or more vertical baffles or substantially vertical baffles that baffle the air as it flows along in the upper part of the vaporizing chamber toward the outlet 2 I. In the present instance we have illustrated two vertical baflle plates 26 and 21, the former of which extends upwardly from the upper bafile 23, and the latter of which extends downwardly from the upper wall of the tank.

The flow of the vapors and air through the vaporizing chamber is indicated by the arrows. If desired, additional baffle plates 28 may be provided in the pipe I! to offer some obstruction to the gases and cause them to be deflected from the straight ath as they flow through.

In order to give an automatic increase of air admitted at the air inlet 20 to the vaporizing chamber, we prefer to provide a small fan 29 located in this inlet, to rotate on an axis coinciding with the axis of the inlet and, if desired, this fan can be placed in the short sleeve 30 that projects upwardly at this opening (see Fig. 1).

If it is desired to prevent radiation of heat from the exhaust header 12, this may be accomplished by covering the header with an apron 3| indicated by the dotted outline in Fig. 1.

Above the venturi the throttle valve 32 is located in the intake, being controlled by a lever and the usual operating link 33.

It should be understood that the fan 29 has 7 blades set with pitch, so that as the incoming air flows past them the fan will be caused to rotate, and the greater the partial vacuum developed in the vaporizing chamber 3, the higher will be the speed of this fan. After the fan acquires speed, it will be evident that it will operate as an impeller, increasing the intake of air; in other,

words, it will mechanically, due to its rotation, increase the quantity of air passing into the vaporizing chamber. When the engine is running at a lower speed, the suction and partial vacuum in the vaporizing chamber 3 will be reduced and the speed of this fan will be reduced.

It will be evident that with this construction a thorough heating and vaporization of the fuel takes place, and a thorough mixture with the incoming air admitted into the vaporizing chamber 3 will be effected. In this way the quantity of air sufiicient for combustion, can be very nicely regulated and without danger of having an excessive quantity of air, which would tend to cool the engine and also tend to reduce the temperature of the explosive mixture passing up through the venturi l3. In other words, while this apparatus will give a proportional admission of air according to the requirements of the engine at different speeds, we prefer to provide additional means for admitting small quantities of air as may be desired at the venturi l8 either below the throat, or above the throat of the venturi, as illustrated in Fig. 1. This means may consist of V-notched small screws 34 of the type sometimes employed in engines for regulating the admission of air in small quantities. These .notches extend longitudinally of the screw and are deeper toward one end.

In starting up the engine, air for combustion Will be drawn past the fan when the starter turns over the engine. As this air flows through the vaporizing chamber 3 it will become charged with fuel vapors, producing an explosive mixture sufficient to start the engine.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention. 1

What we claim is:

1. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a tank for maintaining a quantity ofv volatile liquid fuel, means for passing the hot exhaust gases from the engine through the liquid to vaporize the same, a duct for leading the fuel vapors to the intake, an air inlet for admitting air into the tank so as to mix with the exhaust gases above the liquid level, and so as to flow through the said duct with the fuel vapors, and movable means in said air inlet actuated by the inflowing air for automatically admitting an increased quantity of atmospheric air as the degree of partial vacuum in the engine intake increases incidentally to increased speed of the engine.

2. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a tank for maintaining a quantity of volatile liquid fuel, an exhaust duct for carrying hot exhaust gases from the engine and for passing the same through the liquid fuel to vaporize the gases, means for admitting atmospheric air to the fuel tank to mix with the fuel vapors above the liquid level, an outlet duct leading from the tank for conducting the vaporized fuel and air to the intake and extending along with and surrounding the exhaust duct so as to receive heat from the exhaust duct to preheat the combustible mixture passing to the intake.

3. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a tank for maintaining a quantity of volatile liquid fuel, an exhaust duct having a connecting pipe line for carrying hot exhaust gases from the engine and for passing the same through the liquid fuel to vaporize the same, means for admitting atmospheric air to the fuel tank for mixing with the vaporized fuel, an inlet duct leading from the tank for conducting the vaporized fuel and air to the intake and extending along with and surrounding the said pipe line to take heat from the exhaust duct to preheat the combustible mixture passing to the intake, and means for effecting the mixing of the air and fuel vapors as they pass to the intake.

4. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a receptacle for maintaining a quantity of volatile liquid fuel, an exhaust duct for carrying hot exhaust gases from the engine and for passing the same through the liquid fuel to vaporize the liquid, means for admitting atmospheric air to the fuel receptacle, an inlet duct leading from the receptacle for conducting the vaporized fuel and air to the intake and extending along with the exhaust duct in proximity thereto so as to receive heat from the exhaust duct to preheat the combustible mixture passing to the intake, and means for baffling the combustible vapors and the admitted air to form an efficient mixture of the same before entering the intake.

5. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a fuel tank having a fuel reservoir and having a vaporizing compartment, automatic means for supplying liquid fuel from the reservoir to the vaporizing compartment and for maintaining a quantity of the fuel therein, means for conducting hot gases of combustion from the engine and passing the same upwardly through the liquid fuel in the vaporizing chamber, means for conducting the explosive mixture from the vaporizing chamber to the intake of the engine, means for admitting air to the vaporizing chamber at a point remote from the last-named means, and baffles on the interior of the vaporizing chamber for effecting a thorough mixture of the air and vaporized fuel.

6. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a vaporizing chamber with means for maintaining a quantity of the liquid fuel therein, an inner pipe line for leading exhaust gases from the engine into the vaporizing chamber below the level of the liquid fuel therein, an outer pipe surrounding the said inner pipe line constituting an inlet pipe leading from the vaporizing chamber for conducting the explosive mixture to the intake so that the explosive mixture passing through the inlet pipe is heated by the exhaust gases in the inner pipe, means for admitting air into the vaporizing chamber at a point remote from the point of connection of said inlet pipe to the vaporing chamber, and means for bafiiing the admitted air and the vaporized fuel as the same pass toward the intake to effectively mix the same.

7. In an internal combustion engine apparatus, the combination of an engine having an intake for an explosive mixture, a tank for maintaining a quantity of volatile liquid fuel located at a distance from the engine, an exhaust duct with a connecting pipe line for carrying hot exhaust gases back from the engine to the tank with means for passing the gases through the liquid fuel to vaporize the fuel, means for admitting atmospheric air to the fuel tank, an inlet duct leading from the tank for conducting the vaporized fuel and air to the intake and extending along with and surrounding the pipe so as to receive heat from the exhaust duct to preheat the combustible mixture passing to the intake, means for mixing the air and fuel vapors as they pass to the intake, and means for admitting additional air for combustion adjacent the intake.

RALPH N. CRABTREE. CLAUD A. BROOKS. 

